FDA approved pharmacotherapy options for alcohol use disorders remain limited, with only three currently approved compounds (disulfiram, naltrexone and acamprosate). Recent studies highlight the potential for medications used for the treatment of other indications to be examined for the treatment of alcohol use disorders. Study of additional agents, particularly those that act through novel mechanisms, is needed to expand the range of pharmacotherapy options for alcohol use problems. Extensive preclinical studies indicate that neuroactive steroids medicate important effects of alcohol and support the examination of neuroactive steroid modulators as treatment options for alcohol use problems. Dutasteride, a widely prescribed medication for benign prostatic hypertrophy, bloci<s a key step in the production of neuroactive steroids and represents a promising candidate for treatment of alcohol use disorders. This study will use a randomized placebo controlled design to examine the safety and efficacy of dutasteride to reduce drinking among a sample of 160 men with hazardous levels of alcohol use. It will additionally examine the potential moderation of dutasteride treatment effects by a common missense polymorphism in a neuroactive steroid biosynthetic enzyme that we have previously reported to be associated with alcohol dependence. Identification of genetic predictors of medication response offers the potential for matching alcohol treatment medications with those most likely to respond.